Glancing-Blow Impact Forces by a Barge Train on a Lock Approach Wall

In 1993 Headquarters, U.S. Army Corps of Engineers, issued the first formal Corps-wide analysis procedure providing guidance for analyzing the effects of barge impact loading on navigation structures. The guidance was rescinded in 2001 due to concerns about the conservatism of the computed results for usual and unusual loadings and accuracy with shallow approach impact angles and direct head-on impact. This paper addresses the interpretation of full-scale, low-velocity, controlled barge train (15-barge) impact experiments conducted at the decommissioned Gallipolis Lock at Robert C. Byrd Lock and Dam, Gallipolis Ferry, W.V. Two sets of methodologies were used to interpret the barge-to-wall impact data: (1) the use of the equations of equilibrium combined with an assumed value for the coefficient of friction between the barge train and the stiff-to-rigid wall, and (2) the energy method. A simplified empirical correlation is presented to calculate the maximum impact force as a function of the linear momentum normal to the wall using forces measured during these full-scale impact experiments. This empirical correlation is the basis for new Corps guidance for calculating glancing-blow impact forces.